In existing coring device, the electric motor and the speed reducer are two separate elements, and the drill bit is connected with the speed reducer through a flexible shaft. This structure has lower transmission efficiency, and the flexible shaft is easy to break and bend, the maintenance rate of the instrument is higher.
The stretching of the drill bit of the existing coring device is achieved by four hydraulic cylinders jacking the frame, the rotating and swinging of the drill bit are achieved by other hydraulic cylinder and control mechanism, its structure is complex and multiple power sources are needed.